That project uses autotools to build, which implies that you'll likely require an older (pre-3.6) gnuradio to build the project.

Second of all, you need to link against libgnuradio-runtime. I haven't looked through the project enough to find out why this is; it's likely bitrot due to using a newer Gnuradio. The best solution might be to update the DAB project to use the new CMake-based gr_modtool, but this is likely to be a significant amount of work to get it up and running.